如何仅基于URL路径的某一部分实现重定向？

Hey Peter, nice job getting the basic redirect up and running! To handle that dynamic numeric ID in the category path, we can use either a regular expression (great for pattern matching) or split the path into parts to grab just the post slug. Here are two solid approaches:

Option 1: Regular Expression (Clean Pattern Matching) #

This regex will match any path that starts with /category/ followed by one or more numbers, then capture everything after that final slash (your post slug):

// Match paths like /category/123/my-post or /category/9876/another-post
const categoryPathRegex = /^\/category\/\d+\/(.+)$/;
const pathMatch = window.location.pathname.match(categoryPathRegex);

if (pathMatch) {
  // Extract the captured post slug (e.g., "my-first-post")
  const postSlug = pathMatch[1];
  // Redirect to the new URL with the slug
  window.location.href = `https://myredirect.net/${postSlug}`;
  
  // Optional: Use replace instead of href to avoid adding the old URL to browser history
  // window.location.replace(`https://myredirect.net/${postSlug}`);
}

How this works: #

• ^\/category\/ matches the start of the path exactly as /category/
• \d+ matches one or more digits (the dynamic ID you want to ignore)
• (.+)$ captures everything from the final slash to the end of the path (your post slug)

Option 2: Split Path into Parts (More Explicit Structure Check) #

If you prefer a more readable approach without regex, split the path into segments and validate the structure:

// Split the path into parts, filtering out empty strings from leading/trailing slashes
const pathSegments = window.location.pathname.split('/').filter(segment => segment);

// Check if the path has exactly 3 segments: [category, numeric-id, post-slug]
if (pathSegments.length === 3 && pathSegments[0] === 'category' && !isNaN(pathSegments[1])) {
  const postSlug = pathSegments[2];
  window.location.href = `https://myredirect.net/${postSlug}`;
}

How this works: #

• split('/') breaks the path into an array (e.g., /category/83745/my-first-post becomes ["", "category", "83745", "my-first-post"])
• filter(segment => segment) removes empty strings, leaving ["category", "83745", "my-first-post"]
• We check that there are 3 segments, the first is "category", the second is a number, then grab the third segment as the slug

Quick Notes: #

• Make sure this code runs early in your page load (before any heavy rendering) to avoid unnecessary page content showing up before the redirect
• If you want users to not be able to hit back to the old URL, use window.location.replace() instead of window.location.href
• Both methods will work no matter what the numeric ID is, so you don't have to update the code every time the ID changes

内容的提问来源于stack exchange，提问作者Peter